33 research outputs found
Soliton generation in CaF crystalline whispering gallery mode resonators with negative thermal-optical effects
Calcium fluoride (CaF) crystalline whispering gallery mode resonators
(WGMRs) exhibit ultrahigh intrinsic quality factors and a low power anomalous
dispersion in the communication and mid-infrared bands, making them attractive
platforms for microresonator-based comb generation. However, their unique
negative thermo-optic effects pose challenges when achieving thermal
equilibrium. To our knowledge, our experiments serve as the first demonstration
of soliton microcombs in Q > 109 CaF WGMRs. We observed soliton
mode-locking and bidirectional switching of soliton numbers caused by the
negative thermo-optic effects. Additionally, various soliton formation dynamics
are shown, including breathing and vibrational solitons, which can be
attributed to thermo-photomechanical oscillations. Thus, our results enrich the
soliton generation platform and provide a reference for generating solitons
from WGMRs that comprise other materials with negative thermo-optic effects. In
the future, the ultrahigh quality factor of CaF crystal cavities may enable
the generation of sub-milliwatt-level broad-spectrum soliton combs.Comment: 4 pages,5 pictures,description of soliton generation in a calcium
fluoride whisper gallery mode microresonators with negative thermo-optical
effect,ready for publication in optics lette
Towards a compact soliton microcomb fully referenced on atomic reference
A fully stabilized soliton microcomb is critical for many applications of
optical frequency comb based on microresonators. However, the current
approaches for full frequency stabilization require either external
acousto-optic or electro-optic devices or auxiliary lasers and multiple
phase-locked loops, which compromises the convenience of the system. This study
explores a compact atomic referenced fully stabilized soliton microcomb that
directly uses a rubidium atomic optical frequency reference as the pump source,
and complements the repetition rate (7.3 GHz) of the soliton microcomb was
phase-locked to an atomic-clock-stabilized radio frequency (RF) reference by
mechanically tuning the resonance of the optical resonator. The results
demonstrate that the stability of the comb line (0.66 THz away from the pump
line) is consistent with that of the Rb87 optical reference, attaining a level
of approximately 4 Hz @100 s, corresponding to the frequency stability of 2E-14
@100 s. Furthermore,the frequency reproducibility of the comb line was
evaluated over six days and it was discovered that the standard deviation (SD)
of the frequency of the comb line is 10 kHz, resulting in a corresponding
absolute deviation uncertainty of 1.3E-10, which is technically limited by the
locking range of the soliton repetition rate. The proposed method gives a
low-power and compact solution for fully stabilized soliton micorcombs.Comment: 6 pages, 5 figure
Implementing Quantum Search Algorithm with Metamaterials
Metamaterials, artificially structured electromagnetic (EM) materials, have
enabled the realization of many unconventional electromagnetic properties not
found in nature, such as negative refractive index, magnetic response,
invisibility cloaking and so on. Based on these man-made materials with novel
EM properties, various devices have been designed and realized. However,
quantum analog devices based on metamaterials have not been achieved so far.
Here we designed and printed metamaterials to perform quantum search algorithm.
The structures, comprising of an array of two-dimensional (2D) sub-wavelength
air holes with different radii perforated on the dielectric layer, have been
fabricated by using 3D printing technique. When an incident wave enters in the
designed metamaterials, the profile of beam wavefront is processed iteratively
as it propagates through the metamaterial periodically. After roundtrips,
precisely the same as the efficiency of quantum search algorithm, searched
items will be found with the incident wave all focusing on the marked
positions. Such a metamaterial-based quantum searching simulator may lead to
remarkable achievements in wave-based signal processors.Comment: 22 pages,6 figure
EgoBlur: Responsible Innovation in Aria
Project Aria pushes the frontiers of Egocentric AI with large-scale
real-world data collection using purposely designed glasses with privacy first
approach. To protect the privacy of bystanders being recorded by the glasses,
our research protocols are designed to ensure recorded video is processed by an
AI anonymization model that removes bystander faces and vehicle license plates.
Detected face and license plate regions are processed with a Gaussian blur such
that these personal identification information (PII) regions are obscured. This
process helps to ensure that anonymized versions of the video is retained for
research purposes. In Project Aria, we have developed a state-of-the-art
anonymization system EgoBlur. In this paper, we present extensive analysis of
EgoBlur on challenging datasets comparing its performance with other
state-of-the-art systems from industry and academia including extensive
Responsible AI analysis on recently released Casual Conversations V2 dataset
Genome-wide identiļ¬cation and analysis of heterotic loci in three maize hybrids
Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identiļ¬es 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with completeāincomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the major causes of strong heterosis in these hybrids. Follow-up studies for 17 heterotic loci in an independent experiment using 2225 F2 individuals suggest most heterotic effects are roughly stable between environments with a small variation. Candidate gene analysis for one major heterotic locus (ub3) in maize implies that there may exist some common genes contributing to crop heterosis. These results provide a community resource for genetics studies in maize and new implications for heterosis in plants
The design and protocol of heat-sensitive moxibustion for knee osteoarthritis: a multicenter randomized controlled trial on the rules of selecting moxibustion location
<p>Abstract</p> <p>Background</p> <p>Knee osteoarthritis is a major cause of pain and functional limitation. Complementary and alternative medical approaches have been employed to relieve symptoms and to avoid the side effects of conventional medication. Moxibustion has been widely used to treat patients with knee osteoarthritis. Our past researches suggested heat-sensitive moxibustion might be superior to the conventional moxibustion. Our objective is to investigate the effectiveness of heat-sensitive moxibustion compared with conventional moxibustion or conventional drug treatment.</p> <p>Methods</p> <p>This study consists of a multi-centre (four centers in China), randomised, controlled trial with three parallel arms (A: heat-sensitive moxibustion; B: conventional moxibustion; C: conventional drug group). The moxibustion locations are different from A and B. Group A selects heat-sensitization acupoint from the region consisting of Yin Lingquan(SP9), Yang Lingquan(GB34), Liang Qiu(ST34), and Xue Hai (SP10). Meanwhile, fixed acupoints are used in group B, that is Xi Yan (EX-LE5) and He Ding (EX-LE2). The conventional drug group treats with intra-articular Sodium Hyaluronate injection. The outcome measures above will be assessed before the treatment, the 30 days of the last moxibustion session and 6 months after the last moxibustion session.</p> <p>Discussion</p> <p>This trial will utilize high quality trial methodologies in accordance with CONSORT guidelines. It will provide evidence for the effectiveness of moxibustion as a treatment for moderate and severe knee osteoarthritis. Moreover, the result will clarify the rules of heat-sensitive moxibustion location to improve the therapeutic effect with suspended moxibustion, and propose a new concept and a new theory of moxibustion to guide clinical practices.</p> <p>Trial Registration</p> <p>The trial is registered at Controlled Clinical Trials: ChiCTR-TRC-00000600.</p
The Spatiotemporal Variation of Tree Cover in the Loess Plateau of China after the āGrain for Greenā Project
Analyzing spatiotemporal variation of tree cover could enhance understanding of the environment and promote a sustainable resource use of ecosystems. This study investigated the variation in tree cover in the Loess Plateau after an ecological restoration effort called the āGrain for Green Projectā (GGP). The results show that the proportion of tree covered area in the Loess Plateau changed from 73% to 88%, with the cumulative tree cover fluctuating from approximately 7% to 11%, and the average annual tree cover increased from 10% in 2000 to 12% in 2014. Based on tree cover values over the course of 15 years, the study area was classified into five regions, which provide much more information for spatial assessment of tree cover change in the Loess Plateau spatially. The increase in tree cover value was mainly in the core part of Loess Plateau, the mountains, and the edge of the mountain areas; whereas the values were stable in 36.21% of the area, and a decrease was noted in 5.63% of the area, primarily located in the low plain areas. Approximately 26.36% of the Loess Plateau will show a sustained increase in tree cover in the future. The results of this study will facilitate us to understand the current conditions and development of the GGPās effects, and offer a valuable reference for future detection of tree cover change through geographic information system (GIS) and remote sensing (RS) tools
Genome-wide identiļ¬cation and analysis of heterotic loci in three maize hybrids
Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identiļ¬es 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with completeāincomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the major causes of strong heterosis in these hybrids. Follow-up studies for 17 heterotic loci in an independent experiment using 2225 F2 individuals suggest most heterotic effects are roughly stable between environments with a small variation. Candidate gene analysis for one major heterotic locus (ub3) in maize implies that there may exist some common genes contributing to crop heterosis. These results provide a community resource for genetics studies in maize and new implications for heterosis in plants